Significance of serum uric acid in patients with chronic respiratory failure treated with non-invasive positive pressure ventilation

Intern Med. 2007;46(11):691-7. doi: 10.2169/internalmedicine.46.6120. Epub 2007 Jun 1.


Purpose: The aim of the study was to evaluate serum uric acid (UA) levels before and after non-invasive positive pressure ventilation (NPPV) to assess the utility of serum UA as an indicator of acute exacerbation of chronic respiratory failure (CRF) in patients treated with NPPV.

Methods: We analyzed change in the serum UA level in 29 patients with CRF due to restrictive thoracic disease and treated with NPPV.

Results: After NPPV therapy, PaO2 was significantly increased and PaCO2 was significantly decreased in all patients. Sixty-two percent of patients (18 of 29) showed a decreased serum UA/creatinine (Cr) ratio after NPPV therapy, but, overall, there was no significant change in serum UA/Cr (P=0.0688). The change in serum UA/Cr was not correlated with the changes in PaO2 and PaCO2 after NPPV. When we compared patients in whom serum UA/Cr decreased (n=18) with patients in whom serum UA/Cr did not decrease (n=11), there were significantly fewer patients who suffered CRF exacerbation in the group with a decrease (P=0.0021). Furthermore, the cumulative proportion (Kaplan-Meier) of patients who did not suffer exacerbation of CRF was significantly higher in the group in which serum UA/Cr decreased (P=0.0003).

Conclusions: Our data suggest that serum UA may be a useful clinical indicator of CRF exacerbation in patients treated by NPPV.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • Blood Gas Analysis
  • Bronchodilator Agents / therapeutic use
  • Chronic Disease
  • Creatinine / blood
  • Diuretics / therapeutic use
  • Female
  • Humans
  • Male
  • Middle Aged
  • Positive-Pressure Respiration / methods*
  • Predictive Value of Tests
  • Respiratory Insufficiency / blood*
  • Respiratory Insufficiency / etiology
  • Respiratory Insufficiency / therapy*
  • Retrospective Studies
  • Severity of Illness Index
  • Theophylline / therapeutic use
  • Thoracic Diseases / complications
  • Uric Acid / blood*


  • Biomarkers
  • Bronchodilator Agents
  • Diuretics
  • Uric Acid
  • Creatinine
  • Theophylline